Gravel screen



Sept. 15,1925.

D. a. COOK GRAVEL .SGREEN Filed Jan. 8. 1923 gnwmtoz pay/0 5 Coo/r,

Patented Sept. 15, 1925.

UNI-TED STATES Parent ouster...

D'A'VIDBL COOK, OFFRANKEORT, NEW YORKASSIG'NOR 1 0* .NCME'HQAIYMACHINERY GOMPKNY; 0F FEANKFGRJF, NEW YORK, A CURPOltAMIUN OF YORK.

GRAVEL SCREENL.

Application filed January 8; 1923. Serial No. 611,303.

To all whom it may. concern:

Be it known that I, DAvin B. Coon, a citizen of the United States, residing. at Frankfort, county of. Herhimer, State of New York, have invented acertain new and useful Improvement in Gravel Screens, of

Figure 1 is a: side elevation of a gravel so *eenembodyingthe features of the invention in their preferred form 5 Fig. 9 is a horizontal sectional view taken substantially on the line 2 -2 ofFig. l;

3 is a vertical sectional view, on an enlarged scale, taken on the line 33 of Fig. l, and

Fig. if is-a detail'sectionalview taken on the line 4 i of Fig. 3.

The gravel screen illustrated in the draw ings is provided with a cylindrical screen 2 which is made up of sections of different i'neshes so as to divide the material into different grades. The screen 2 is arranged with its axis slightly inclined dbwnwardly and rearwardly to' the horizontal, and is mounted on a shaft 4 that extends axially through the screen, the shaft being provided with suitable spiders 6 to which the screen is secured. The rear end of the shaft 4 extends a distance beyond the end of the screen and is journaled in a bearing 8 which is mounted on a cross-beam 10 of a supporting frame 12 for the screen. The forward end of the shaft t is spaced a distance from the forward end of the screen and is journaled in a bearing block 14 which is secured by bolts 16 to the rear ends of hangers 18 that converge outwardly and forwardly from the screen, the hangers being secured on cross bars 20 of the frame. A gravel chute 22 is arranged between the hangers 18 and is inclined downwardly and rearwardly to bring its; delivery end beneath the forward'end of the shaft 2, the end of' the shaft and the bearingld being. spaced inwardly from the forward end of the screen so as to enable the chute to be thus positionedv Gravel screens of the; type above indicated are usually mounted onthetop of a screen bin, and an elevator of the chain and bucket: type is employed for conveyingthe material to be screened from th'e ground to the screen chute 22. hen the screen is thus used in connection with a screen bin and elevator, it is customary to drive the screen from a pulley or sprocliet on the bucket chain ing shaft at the top of the elevator. Here tofore, the driving connection between the screen and said pulley orsprocket has usually consisted of speed reducing gearing connected with the extreme rear end'of the screen shaft, the gearing being connected with the driving, pulley or sprocket by means of a belt or chain extending over'the length of the screen. As the screen cylinder is of considerable length; this driving connection necessitates the use of a belt or sprocket chain of so great a length as tobe objectionable. Moreoveniwhen the screen is in operation the weight of the gravel therein is greater near its front end than at its rear end, with the resultthat the drivingof'the screen through mechanism connected with the extreme rear end of the screen shaft causes a reat torsional strain to be placed on the shaft which makes-it necessary to use a very heavy shaft. The drivingme'chanism for the screen could not be connected with the forward end of the screen shaft as this end of the shaft must be: spaced bacli' from the forwarde'nd of th'e screen to'allbw for the gravel chute. Also it was not thought practical to connect the speed reducing gearing of the driving mechanism with the forward end of the screen as the sand and dust always present about the forward end of the screen during its opera tion would soon clog up and grind off the teeth of the gearing.

In the gravel screen illustratedin the drawings, however, I have provided a simple, strong and durable driving mechanism for the screen cylinder that overcomes the disadvantages above described of the prior construction. As shown my improved driving mechanism comprises an annular gear 26 that is secured on the forward end of the screen. The gear 26 is provided with a cylindrical flange 28 that fits into the forward end of the screen and is secured thereto by bolts or screws 30; and with an inwardly projecting flange 32 that serves to prevent the gravel from working out of the screen, this gear as a whole serving as a bracing rim for the forward end of the screen. The gear is further provided with radially extending spoke-like teeth 34, the upper ends of which are connected by a rim 36 integral therewith. The teeth 34 are engaged by the teeth of a slightly beveled spur gear 38 carried by a short shaft 40 which is arranged back of the gear 26 and transverse to the axis of the screen shaft. The shaft 40 extends through and is journaled in a bearing on theupper end of a bracket 42 secured to the screen frame. A sprocket wheel 44 is secured on the outer end of the shaft 40, the sprocket being adapted to be connected by a chain with a sprocket on the bucket chain carrying shaft at the upper end of the gravel elevator.

It has been found that with this construction any dust or sand lodging on the teeth of the gear 26 will readily work out from the space between the teeth so that there is no danger of the teeth becoming clogged, or materially injured by the grinding action of the sand. It has also been found thata relatively light screen carrying shaft of hollow construction may be employed in place of the usual solid and heavy shaft as very little torsional strain is placed on the shaft. My improved driving mechanism also does away with the use of a long chain or belt, and the power is applied to the screen where the load is the greatest.

As will be evident to those skilled in the art my invention permits of various modifications without departing from the spirit thereof or the scope of the appended claims.

That I claim is:

1. A screen of the class described having, in combination, a shaft slightly inclined downwardly and rearwardly, bearings for the ends of the shaft, a cylindrical screen mounted on the shaft, means for directing material into the forward end of the screen beneath the forward end of the shaft, and means for driving the screen comprising an annular gear having an inner rim mounted directly on the forward end of the screen, an outer rim surrounding the inner rim, and spoke-like teeth extending between the rims having spaces between them, and a driving pinion arranged back of said gear with itsaxis arranged substantially transverse to the axis of the screen, and operatively engaging said teeth.

2. A screen of the class described having, in combination, a shaft slightly inclined downwardly and rearwardly t0 the horizontal, bearings for the ends of the shaft, a cylindrical screen mounted on the shaft, means fordirecting material into the forward end of the screen beneath the forward end of the shaft, and means for driving the screen comprising an annular gear mounted directly on the forward end of the screen and having spoke-like teeth having spaces between them, and a driving pinion arranged back of said gear, having its axis arranged substantially transverse to the axis of the screen and operatively engaging said teeth.

3. A screen of the class described having, in combination, a cylindrical screen having its axis inc-lined downwardly and rearwardly, means for directing material into the forward end of the screen, and means for driving the screen comprising an annular gear having a cylindrical flange telescopingly engaging and secured to the forward end of the screen, having an outer rim arranged concentrically with said flange and having radially projecting spokelike teeth having open spaces between them and extending between said flange and rim, and a driving pinion arranged back of said gear, having its axis arranged substantially trans verse to the axis of the screen and operatively engaging said teeth. 4

DAVID B. COOK. 

